DESCRIPTION: This proposal is a continuation of studies on normal and abnormal synthesis in hemoglobinopathies in sickle cell anemia and thalassemia. These hereditary anemias affect people from wide geographic areas, including the Mediterranean region, Africa,Middle East, Indian subcontinent and Southeast Asia. Studies will concentrate on three different areas which will contribute to the improved management of these disorders. 1) Research in the past grant years has indicated that the reverse dot blot is the most simple nonradioactive method for detecting mutations in sickle cell anemia. Hence, during coming years, analyses will be designed to cover most of the mutations in different ethnic groups and geographic areas in order to expedite prenatal diagnosis. Also, because fetal cells are known to cross into maternal circulation early in pregnancy, research will be performed on simple methods of isolating fetal cells from mother s blood in order to provide a noninvasive form of fetal DNA test for sickle cell anemia and thalassemia. 2) Investigations will be conducted on in vivo protein-DNA interactions between the globin control regions to allow a glimpse into the mechanism of globin gene control in vivo, as these interactions are important for tissue-specific and developmental-specific expression of the globin genes. The trans- acting proteins that are bound to these critical sequences will be characterized. These studies will lead to the understanding of control of globin gene expression and hemoglobin switching and may provide insight into new treatment modalities. 3) Methods of delivery of globin genes into erythroid cells to allow high level of expression will be investigated through the use of trans-acting factor binding DNA motifs which enhance globin gene expression. Chimeric genes which express gamma globin persistently in the adult red cell will also be tested. Also, the use of adeno-associated virus vectors will be compared to retroviral delivery. These three avenues of investigation may help to prevent homozygous disease and lead to new insight in the treatment of sickle cell anemia and thalassemia.